According to the dsm-iv, is a clinically significant behavioral and psychological syndrome or pattern that occurs in an individual and that is associated with present distress or disability or with a significantly increased risk of suffering death, pain, disability, or an important loss of freedom.

Explanation:

POST TRAUMATIC STRESS DISORDER is a symptom of someone who has been exposed to traumatic events, like war, physical beatings etc...

makes the individual suffer with vivid nightmares or night terrors, paranoia, etc. many with this illness try to self-medicate with alcohol, elicid drugs, to cope with these symptoms.